If possible can someone post a link to the guy's post where he enlarges the snorkel.
Thanks

 

They don't enlarge them, they replace them with the snorkel from a KDX200 or 220. If you ride off road and are concerned with any water getting into the air box get the snorkel. If you ride dry conditions or road you can simply pull the snorkel. I've done both, on my KLX650 which was mainly road I pulled the snorkel (couldn't get a bigger one anyway) but on the 250 it may be possible to dump water into the air box so I got the KDX snorkel. By the way my resource for this was D Pippin's site, which is linked in my document I have in my signature for the hop ups. Pippin's put a lot of time into his KLX hop ups and saves us a lot of time with his experience.

Kawasaki part number 14073-1577 You can see in the picture the snorkel is roughly twice the cross sectional area and is almost as big in cross section as the rubber boot between the air box and carb.

 

Thanks klx678.
I have seen something somewhere where the snorkel is enlarged.
Please can you let me know where to find your signature and the hop ups?
Thanks

 

Just found this again on YouTube. I thought it was on this forum.
Certainly worth considering imo. Would welcome others comments.

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If there is a step between his extension and the snorkel it will create a large wave of turbulence inside at the step, the step being a bit of a kicker, to borrow a trials term, on the air as it hits said step. It's like putting a bigger intake on the head than the port into the head, the step causes a flow problem. One of the reasons tuners will smooth the transition and match the ports to the manifolds.. The transition has to be smooth otherwise the step creates big turbulence waves.

Back in my two stroke days one trick was polishing ports, which we all did... until Gordon Jennings pointed out that any wave in the surface creates a large wave, that many of the best port companies either did serious work to keep the surface smooth and straight or they would bead blast the port. Small bumps of the bead blast would actually hold a bit of the fuel smoothing the surface and/or they would create small turbulence waves on the surface, but much smaller and less flow resistance than the large turbulence waves of the polished but wavy port.

I will say again, and it is worth emphasizing, the 250 intake snorkel is half the size of the KDX snorkel. The 250 snorkel is actually smaller cross section than the air box to carb boot where the KDX is near identical in cross sectional area. That would make a big difference at high rpm. The longer but smaller snorkel is likely used to cut down engine noise since they do have to meet noise standards.

I don't know if I go full on with his ram air effect in that few drag racers actually put long runner scoops on their intakes, they're usually fairly short and direct similar to the stock KDX tube. Now the carb set up may use long intake runners or a tunnel ram manifold after the carbs, but that's a different situation in flow.

Then there is the consideration he overlooked, a two stroke draws air in at twice the rate of a four stroke, since it is drawing in air with every rotation of the crank, not every other one like a four stroke, so it requires higher volume in spite of running at lower speed. So if that is true, the 220 is pulling in somewhere near twice the air at the same rpm as a 250.

He had no comment of any head to head comparison in performance. It would be interesting to see a head to head test of the extended snorkel though. A dyno run would require some sort of higher speed fan blowing air in at around 80 mph with rider on the bike to see if the numbers show a difference. See if it actually flows better. It may. I don't know. In my case I don't really care much since if I want to go that fast I'm on the street bike. I don't spend a lot of time running the 250 at 80 mph or 70 mph for that matter. It's mainly my true dual sport bike.

Then there is the one snorkel I've never seen, the KLX300 snorkel, which may or may not be as big as the KDX snorkel. It shows the longer top intake snout, but I don't plan on buying one to see. Mostly because I have the 220 snorkel already and it does what I need. Anyone have a 300 to tell us if it's bigger?